A method comprising incorporation of an inorganic polymer precursor of a grain growth inhibitor into superfine materials or intermediates useful for the production of superfine materials. The precursor/nanostructured material composite is optionally heat treated at a temperature below the grain growth temperature of the superfine material in order to more effectively disperse the precursor. The composites are then heat treated at a temperature effective to decompose the precursor and to form superfine materials having grain growth inhibitors uniformly distributed at the grain boundaries. Synthesis of the inorganic polymer solution comprises forming an inorganic polymer from a solution of metal salts, filtering the polymer, and drying. Alloying additives as well as grain growth inhibitors may be incorporated into the superfine materials.